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view src/http/ngx_http_upstream_round_robin.c @ 7585:746567d633ac

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Win32: improved fallback on FormatMessage() errors. FormatMessage() seems to return many errors which essentially indicate that the language in question is not available. At least the following were observed in the wild and during testing: ERROR_MUI_FILE_NOT_FOUND (15100) (ticket #1868), ERROR_RESOURCE_TYPE_NOT_FOUND (1813). While documentation says it should be ERROR_RESOURCE_LANG_NOT_FOUND (1815), this doesn't seem to be the case. As such, checking error code was removed, and as long as FormatMessage() returns an error, we now always try the default language.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 21 Oct 2019 19:06:12 +0300
parents b99cbafd51da
children 90cc7194e993
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>


#define ngx_http_upstream_tries(p) ((p)->number                               \
                                    + ((p)->next ? (p)->next->number : 0))


static ngx_http_upstream_rr_peer_t *ngx_http_upstream_get_peer(
    ngx_http_upstream_rr_peer_data_t *rrp);

#if (NGX_HTTP_SSL)

static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc,
    void *data);
static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc,
    void *data);

#endif


ngx_int_t
ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_url_t                      u;
    ngx_uint_t                     i, j, n, w;
    ngx_http_upstream_server_t    *server;
    ngx_http_upstream_rr_peer_t   *peer, **peerp;
    ngx_http_upstream_rr_peers_t  *peers, *backup;

    us->peer.init = ngx_http_upstream_init_round_robin_peer;

    if (us->servers) {
        server = us->servers->elts;

        n = 0;
        w = 0;

        for (i = 0; i < us->servers->nelts; i++) {
            if (server[i].backup) {
                continue;
            }

            n += server[i].naddrs;
            w += server[i].naddrs * server[i].weight;
        }

        if (n == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no servers in upstream \"%V\" in %s:%ui",
                          &us->host, us->file_name, us->line);
            return NGX_ERROR;
        }

        peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
        if (peers == NULL) {
            return NGX_ERROR;
        }

        peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
        if (peer == NULL) {
            return NGX_ERROR;
        }

        peers->single = (n == 1);
        peers->number = n;
        peers->weighted = (w != n);
        peers->total_weight = w;
        peers->name = &us->host;

        n = 0;
        peerp = &peers->peer;

        for (i = 0; i < us->servers->nelts; i++) {
            if (server[i].backup) {
                continue;
            }

            for (j = 0; j < server[i].naddrs; j++) {
                peer[n].sockaddr = server[i].addrs[j].sockaddr;
                peer[n].socklen = server[i].addrs[j].socklen;
                peer[n].name = server[i].addrs[j].name;
                peer[n].weight = server[i].weight;
                peer[n].effective_weight = server[i].weight;
                peer[n].current_weight = 0;
                peer[n].max_conns = server[i].max_conns;
                peer[n].max_fails = server[i].max_fails;
                peer[n].fail_timeout = server[i].fail_timeout;
                peer[n].down = server[i].down;
                peer[n].server = server[i].name;

                *peerp = &peer[n];
                peerp = &peer[n].next;
                n++;
            }
        }

        us->peer.data = peers;

        /* backup servers */

        n = 0;
        w = 0;

        for (i = 0; i < us->servers->nelts; i++) {
            if (!server[i].backup) {
                continue;
            }

            n += server[i].naddrs;
            w += server[i].naddrs * server[i].weight;
        }

        if (n == 0) {
            return NGX_OK;
        }

        backup = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
        if (backup == NULL) {
            return NGX_ERROR;
        }

        peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
        if (peer == NULL) {
            return NGX_ERROR;
        }

        peers->single = 0;
        backup->single = 0;
        backup->number = n;
        backup->weighted = (w != n);
        backup->total_weight = w;
        backup->name = &us->host;

        n = 0;
        peerp = &backup->peer;

        for (i = 0; i < us->servers->nelts; i++) {
            if (!server[i].backup) {
                continue;
            }

            for (j = 0; j < server[i].naddrs; j++) {
                peer[n].sockaddr = server[i].addrs[j].sockaddr;
                peer[n].socklen = server[i].addrs[j].socklen;
                peer[n].name = server[i].addrs[j].name;
                peer[n].weight = server[i].weight;
                peer[n].effective_weight = server[i].weight;
                peer[n].current_weight = 0;
                peer[n].max_conns = server[i].max_conns;
                peer[n].max_fails = server[i].max_fails;
                peer[n].fail_timeout = server[i].fail_timeout;
                peer[n].down = server[i].down;
                peer[n].server = server[i].name;

                *peerp = &peer[n];
                peerp = &peer[n].next;
                n++;
            }
        }

        peers->next = backup;

        return NGX_OK;
    }


    /* an upstream implicitly defined by proxy_pass, etc. */

    if (us->port == 0) {
        ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                      "no port in upstream \"%V\" in %s:%ui",
                      &us->host, us->file_name, us->line);
        return NGX_ERROR;
    }

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.host = us->host;
    u.port = us->port;

    if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "%s in upstream \"%V\" in %s:%ui",
                          u.err, &us->host, us->file_name, us->line);
        }

        return NGX_ERROR;
    }

    n = u.naddrs;

    peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
    if (peers == NULL) {
        return NGX_ERROR;
    }

    peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
    if (peer == NULL) {
        return NGX_ERROR;
    }

    peers->single = (n == 1);
    peers->number = n;
    peers->weighted = 0;
    peers->total_weight = n;
    peers->name = &us->host;

    peerp = &peers->peer;

    for (i = 0; i < u.naddrs; i++) {
        peer[i].sockaddr = u.addrs[i].sockaddr;
        peer[i].socklen = u.addrs[i].socklen;
        peer[i].name = u.addrs[i].name;
        peer[i].weight = 1;
        peer[i].effective_weight = 1;
        peer[i].current_weight = 0;
        peer[i].max_conns = 0;
        peer[i].max_fails = 1;
        peer[i].fail_timeout = 10;
        *peerp = &peer[i];
        peerp = &peer[i].next;
    }

    us->peer.data = peers;

    /* implicitly defined upstream has no backup servers */

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_uint_t                         n;
    ngx_http_upstream_rr_peer_data_t  *rrp;

    rrp = r->upstream->peer.data;

    if (rrp == NULL) {
        rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
        if (rrp == NULL) {
            return NGX_ERROR;
        }

        r->upstream->peer.data = rrp;
    }

    rrp->peers = us->peer.data;
    rrp->current = NULL;
    rrp->config = 0;

    n = rrp->peers->number;

    if (rrp->peers->next && rrp->peers->next->number > n) {
        n = rrp->peers->next->number;
    }

    if (n <= 8 * sizeof(uintptr_t)) {
        rrp->tried = &rrp->data;
        rrp->data = 0;

    } else {
        n = (n + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t));

        rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t));
        if (rrp->tried == NULL) {
            return NGX_ERROR;
        }
    }

    r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
    r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
    r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
    r->upstream->peer.set_session =
                               ngx_http_upstream_set_round_robin_peer_session;
    r->upstream->peer.save_session =
                               ngx_http_upstream_save_round_robin_peer_session;
#endif

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_resolved_t *ur)
{
    u_char                            *p;
    size_t                             len;
    socklen_t                          socklen;
    ngx_uint_t                         i, n;
    struct sockaddr                   *sockaddr;
    ngx_http_upstream_rr_peer_t       *peer, **peerp;
    ngx_http_upstream_rr_peers_t      *peers;
    ngx_http_upstream_rr_peer_data_t  *rrp;

    rrp = r->upstream->peer.data;

    if (rrp == NULL) {
        rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
        if (rrp == NULL) {
            return NGX_ERROR;
        }

        r->upstream->peer.data = rrp;
    }

    peers = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peers_t));
    if (peers == NULL) {
        return NGX_ERROR;
    }

    peer = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peer_t)
                                * ur->naddrs);
    if (peer == NULL) {
        return NGX_ERROR;
    }

    peers->single = (ur->naddrs == 1);
    peers->number = ur->naddrs;
    peers->name = &ur->host;

    if (ur->sockaddr) {
        peer[0].sockaddr = ur->sockaddr;
        peer[0].socklen = ur->socklen;
        peer[0].name = ur->name.data ? ur->name : ur->host;
        peer[0].weight = 1;
        peer[0].effective_weight = 1;
        peer[0].current_weight = 0;
        peer[0].max_conns = 0;
        peer[0].max_fails = 1;
        peer[0].fail_timeout = 10;
        peers->peer = peer;

    } else {
        peerp = &peers->peer;

        for (i = 0; i < ur->naddrs; i++) {

            socklen = ur->addrs[i].socklen;

            sockaddr = ngx_palloc(r->pool, socklen);
            if (sockaddr == NULL) {
                return NGX_ERROR;
            }

            ngx_memcpy(sockaddr, ur->addrs[i].sockaddr, socklen);
            ngx_inet_set_port(sockaddr, ur->port);

            p = ngx_pnalloc(r->pool, NGX_SOCKADDR_STRLEN);
            if (p == NULL) {
                return NGX_ERROR;
            }

            len = ngx_sock_ntop(sockaddr, socklen, p, NGX_SOCKADDR_STRLEN, 1);

            peer[i].sockaddr = sockaddr;
            peer[i].socklen = socklen;
            peer[i].name.len = len;
            peer[i].name.data = p;
            peer[i].weight = 1;
            peer[i].effective_weight = 1;
            peer[i].current_weight = 0;
            peer[i].max_conns = 0;
            peer[i].max_fails = 1;
            peer[i].fail_timeout = 10;
            *peerp = &peer[i];
            peerp = &peer[i].next;
        }
    }

    rrp->peers = peers;
    rrp->current = NULL;
    rrp->config = 0;

    if (rrp->peers->number <= 8 * sizeof(uintptr_t)) {
        rrp->tried = &rrp->data;
        rrp->data = 0;

    } else {
        n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
                / (8 * sizeof(uintptr_t));

        rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t));
        if (rrp->tried == NULL) {
            return NGX_ERROR;
        }
    }

    r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
    r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
    r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
    r->upstream->peer.set_session = ngx_http_upstream_empty_set_session;
    r->upstream->peer.save_session = ngx_http_upstream_empty_save_session;
#endif

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_int_t                      rc;
    ngx_uint_t                     i, n;
    ngx_http_upstream_rr_peer_t   *peer;
    ngx_http_upstream_rr_peers_t  *peers;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "get rr peer, try: %ui", pc->tries);

    pc->cached = 0;
    pc->connection = NULL;

    peers = rrp->peers;
    ngx_http_upstream_rr_peers_wlock(peers);

    if (peers->single) {
        peer = peers->peer;

        if (peer->down) {
            goto failed;
        }

        if (peer->max_conns && peer->conns >= peer->max_conns) {
            goto failed;
        }

        rrp->current = peer;

    } else {

        /* there are several peers */

        peer = ngx_http_upstream_get_peer(rrp);

        if (peer == NULL) {
            goto failed;
        }

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                       "get rr peer, current: %p %i",
                       peer, peer->current_weight);
    }

    pc->sockaddr = peer->sockaddr;
    pc->socklen = peer->socklen;
    pc->name = &peer->name;

    peer->conns++;

    ngx_http_upstream_rr_peers_unlock(peers);

    return NGX_OK;

failed:

    if (peers->next) {

        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0, "backup servers");

        rrp->peers = peers->next;

        n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
                / (8 * sizeof(uintptr_t));

        for (i = 0; i < n; i++) {
            rrp->tried[i] = 0;
        }

        ngx_http_upstream_rr_peers_unlock(peers);

        rc = ngx_http_upstream_get_round_robin_peer(pc, rrp);

        if (rc != NGX_BUSY) {
            return rc;
        }

        ngx_http_upstream_rr_peers_wlock(peers);
    }

    ngx_http_upstream_rr_peers_unlock(peers);

    pc->name = peers->name;

    return NGX_BUSY;
}


static ngx_http_upstream_rr_peer_t *
ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp)
{
    time_t                        now;
    uintptr_t                     m;
    ngx_int_t                     total;
    ngx_uint_t                    i, n, p;
    ngx_http_upstream_rr_peer_t  *peer, *best;

    now = ngx_time();

    best = NULL;
    total = 0;

#if (NGX_SUPPRESS_WARN)
    p = 0;
#endif

    for (peer = rrp->peers->peer, i = 0;
         peer;
         peer = peer->next, i++)
    {
        n = i / (8 * sizeof(uintptr_t));
        m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));

        if (rrp->tried[n] & m) {
            continue;
        }

        if (peer->down) {
            continue;
        }

        if (peer->max_fails
            && peer->fails >= peer->max_fails
            && now - peer->checked <= peer->fail_timeout)
        {
            continue;
        }

        if (peer->max_conns && peer->conns >= peer->max_conns) {
            continue;
        }

        peer->current_weight += peer->effective_weight;
        total += peer->effective_weight;

        if (peer->effective_weight < peer->weight) {
            peer->effective_weight++;
        }

        if (best == NULL || peer->current_weight > best->current_weight) {
            best = peer;
            p = i;
        }
    }

    if (best == NULL) {
        return NULL;
    }

    rrp->current = best;

    n = p / (8 * sizeof(uintptr_t));
    m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));

    rrp->tried[n] |= m;

    best->current_weight -= total;

    if (now - best->checked > best->fail_timeout) {
        best->checked = now;
    }

    return best;
}


void
ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
    ngx_uint_t state)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    time_t                       now;
    ngx_http_upstream_rr_peer_t  *peer;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "free rr peer %ui %ui", pc->tries, state);

    /* TODO: NGX_PEER_KEEPALIVE */

    peer = rrp->current;

    ngx_http_upstream_rr_peers_rlock(rrp->peers);
    ngx_http_upstream_rr_peer_lock(rrp->peers, peer);

    if (rrp->peers->single) {

        peer->conns--;

        ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
        ngx_http_upstream_rr_peers_unlock(rrp->peers);

        pc->tries = 0;
        return;
    }

    if (state & NGX_PEER_FAILED) {
        now = ngx_time();

        peer->fails++;
        peer->accessed = now;
        peer->checked = now;

        if (peer->max_fails) {
            peer->effective_weight -= peer->weight / peer->max_fails;

            if (peer->fails >= peer->max_fails) {
                ngx_log_error(NGX_LOG_WARN, pc->log, 0,
                              "upstream server temporarily disabled");
            }
        }

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                       "free rr peer failed: %p %i",
                       peer, peer->effective_weight);

        if (peer->effective_weight < 0) {
            peer->effective_weight = 0;
        }

    } else {

        /* mark peer live if check passed */

        if (peer->accessed < peer->checked) {
            peer->fails = 0;
        }
    }

    peer->conns--;

    ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
    ngx_http_upstream_rr_peers_unlock(rrp->peers);

    if (pc->tries) {
        pc->tries--;
    }
}


#if (NGX_HTTP_SSL)

ngx_int_t
ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_int_t                      rc;
    ngx_ssl_session_t             *ssl_session;
    ngx_http_upstream_rr_peer_t   *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
    int                            len;
    const u_char                  *p;
    ngx_http_upstream_rr_peers_t  *peers;
    u_char                         buf[NGX_SSL_MAX_SESSION_SIZE];
#endif

    peer = rrp->current;

#if (NGX_HTTP_UPSTREAM_ZONE)
    peers = rrp->peers;

    if (peers->shpool) {
        ngx_http_upstream_rr_peers_rlock(peers);
        ngx_http_upstream_rr_peer_lock(peers, peer);

        if (peer->ssl_session == NULL) {
            ngx_http_upstream_rr_peer_unlock(peers, peer);
            ngx_http_upstream_rr_peers_unlock(peers);
            return NGX_OK;
        }

        len = peer->ssl_session_len;

        ngx_memcpy(buf, peer->ssl_session, len);

        ngx_http_upstream_rr_peer_unlock(peers, peer);
        ngx_http_upstream_rr_peers_unlock(peers);

        p = buf;
        ssl_session = d2i_SSL_SESSION(NULL, &p, len);

        rc = ngx_ssl_set_session(pc->connection, ssl_session);

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                       "set session: %p", ssl_session);

        ngx_ssl_free_session(ssl_session);

        return rc;
    }
#endif

    ssl_session = peer->ssl_session;

    rc = ngx_ssl_set_session(pc->connection, ssl_session);

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "set session: %p", ssl_session);

    return rc;
}


void
ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_ssl_session_t             *old_ssl_session, *ssl_session;
    ngx_http_upstream_rr_peer_t   *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
    int                            len;
    u_char                        *p;
    ngx_http_upstream_rr_peers_t  *peers;
    u_char                         buf[NGX_SSL_MAX_SESSION_SIZE];
#endif

#if (NGX_HTTP_UPSTREAM_ZONE)
    peers = rrp->peers;

    if (peers->shpool) {

        ssl_session = ngx_ssl_get0_session(pc->connection);

        if (ssl_session == NULL) {
            return;
        }

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                       "save session: %p", ssl_session);

        len = i2d_SSL_SESSION(ssl_session, NULL);

        /* do not cache too big session */

        if (len > NGX_SSL_MAX_SESSION_SIZE) {
            return;
        }

        p = buf;
        (void) i2d_SSL_SESSION(ssl_session, &p);

        peer = rrp->current;

        ngx_http_upstream_rr_peers_rlock(peers);
        ngx_http_upstream_rr_peer_lock(peers, peer);

        if (len > peer->ssl_session_len) {
            ngx_shmtx_lock(&peers->shpool->mutex);

            if (peer->ssl_session) {
                ngx_slab_free_locked(peers->shpool, peer->ssl_session);
            }

            peer->ssl_session = ngx_slab_alloc_locked(peers->shpool, len);

            ngx_shmtx_unlock(&peers->shpool->mutex);

            if (peer->ssl_session == NULL) {
                peer->ssl_session_len = 0;

                ngx_http_upstream_rr_peer_unlock(peers, peer);
                ngx_http_upstream_rr_peers_unlock(peers);
                return;
            }

            peer->ssl_session_len = len;
        }

        ngx_memcpy(peer->ssl_session, buf, len);

        ngx_http_upstream_rr_peer_unlock(peers, peer);
        ngx_http_upstream_rr_peers_unlock(peers);

        return;
    }
#endif

    ssl_session = ngx_ssl_get_session(pc->connection);

    if (ssl_session == NULL) {
        return;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "save session: %p", ssl_session);

    peer = rrp->current;

    old_ssl_session = peer->ssl_session;
    peer->ssl_session = ssl_session;

    if (old_ssl_session) {

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                       "old session: %p", old_ssl_session);

        /* TODO: may block */

        ngx_ssl_free_session(old_ssl_session);
    }
}


static ngx_int_t
ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data)
{
    return NGX_OK;
}


static void
ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data)
{
    return;
}

#endif